(a)
rs x st = tu 2
(b)
yes it is possible the formula is in part a, but we're given just the side rt and st, not rs, but not to worry we can get rs with subtraction. we can do 9-4=5 for rs. now we can plug in our values to find tu
5x4 = tu 2
simplify with algebra
20 = tu
FINAL ANSWER